1. Technical Field
The present disclosure relates to a display device having electrically controlled birefringence.
2. Discussion of the Related Art
A liquid crystal display (LCD) device displays an image by using a liquid crystal layer. Since the LCD device may be thinner, lighter, and use a low driving voltage compare to other display devices, the LCD device has gained wide acceptance.
The LCD device includes a liquid crystal panel having color filters to display color and a light supplying unit having a light source such as a cold cathode florescent lamp (CCFL) and a light emitting diode (LED) to provide light to the liquid crystal panel.
Due to the characteristic of the liquid crystal layer, image quality of the LCD device can deteriorate when users watch the panel from an upper side or a tower side of the liquid crystal panel. In other words, gray inversion can occur. Various methods have been developed to reduce the gray inversion in oblique view. One of them is a multi domain method such as an in plane switching (IPS) mode or a patterned vertical alignment (PVA) mode. However, the IPS mode or the PVA mode requires an additional process and a structure for domain dividing. Another approach is an electrically controlled birefringence (ECB) mode with wide viewing films. While ECB mode may perform wide viewing angle easily when wide viewing films are applied, gray inversion in high gray levels can be more severe when viewed from an upper direction, and can be more yellowish from a side view direction.